2. A ring for determining deflection, having its outer periphery concentric, and having its side walls progressively increasing in thickness from the transverse diameter of the ring towards the top and bottom of the ring, the top and bottom portions of the ring being of greater width and thickness than the side Walls of the ring.
3. A proving ring, comprising a metallic ring 4 having its side walls cut away between its top and bottom portions to reduce the width of the side walls and to contribute to form enlarged heads at the top and bottom of the ring, the outer periphery of the ring being concentric, and the inner periphery of the ring being eccentric and gradually increasing in thickness from the transverse diameter of the ring to said enlarged heads HAROLD C. SUNDBY.
REFERENCES CITED The following references are of record in the ile of this patent: